My right side (passenger side) back up lamp has intermittently worked for about 2 weeks. Today I pulled the taillight cover off and replaced the bulb. Since doing that, I have no taillights on the right side? Both bulbs are good but I have no voltage to either of the 2 taillight sockets? I have no voltage at the multiwire connector for those 2 sockets. Every other bulb works even the brake lamp filament in the one bulb in the dead taillight socket. I pulled all 3 fuse box covers off and tested each fuse with a test light. Every fuse lit up the test light. What could I have done by simply pulling out the taillight array to change one bulb? I gave up when it became dark outside.

 

Besides the obvious: ensure connector is properly seated (mine was once knocked out after too many beach chairs put in trunk); while poor bulb connections are common, doubt it'd hit all bulbs at once.

As I recall, the entire bulb assembly is grounded through the thin black wire at the bottom of circuit board. This heats up due to its size causing light problems. You mayy see scorch marks where this wire meets the connector assembly. There is a fix posted here to add a proper ground wire, I had to do it once. Take a meter and measure from circuit board ground trace to chassis ground. A poor or open ground would cause this.

Heck you could hold a wire to the circuit board ground chase from a chassis ground to test if you don't have a meter. The lights will light through the ground wire in your hands.

John

 

Thank you! If it is a poor or lack of ground, why would the rear fogs work and brake lights and turn signal bulbs? My 2 taillight sockets have no voltage to the sockets, no voltage to the multi wire plug? I will add a ground wire tonight after work.

 

Ah you are correct. I must have skimmed and thought this was all

Let me thinkttys

 

I didn't want to forget about your question. You wrote: Every other bulb works even the brake lamp filament in the one bulb in the dead taillight socket. Partner I need help understanding this statement please.

I'm just trying to get a handle on everything you have eliminated. In the mean time let's assume you have verified all fuses are good, and you looked for 12volts at the connector to the right rear light circuit board, nothing there. Given the above this tells me the wire to this trace on the circuit board is open.

Let's think about the connector. There is a multi wire connector that plugs into the circuit board. I am guessing that you checked for 12 volts at the connector's female pin. Is it possible that the wire seperated from this pin at the bottom of the connector where the wire connects to the pin? That would explain everything.

I can't imagine left and right bulbs being on 2 different fuses. If that's true, one should be able to see continuity between the hot trace on the left and right sides for these bulbs. (IOW between the circuit trace to this bulb on each side)

If you were to hook up your ohm meter, car power off, and measure resistance between these two traces and you found it to be a fractional reading (nearly zero ohms) then my hypothesis of an open wire is false. This proves that any power you get on the left side you are getting on the right side - you can look for dirty connections or bad bulbs. If you measure and it is open this proves that continuity is broken somewhere on the way to the right rear light's connector assuming my hypothesis is true and these are on the same circuit.

Would you like me to measure mine to ensure there is continuity between left and right power wires to the left and right rear circuit board's trace for these bulbs? Let me know after you checked the wire to pin connection.

John

 

John, I will if the wire integrity proves OK on the female wire connector. Regarding the brake light socket, as you know both taillight sockets require dual filament bulbs but only one has 2 connectors within the socket. So both taillight pins in both sockets are dead. My thought is these two sockets share a common power wire at the connector and the power is split on the circuit board.

 

Grantorino62, I'll check in later this afternoon. Please let me know if you need the continuity tested on a working car.

John

 

oh yeah.please tell me the wire color or position in the modular female connector on each side if you do make the request. It'll save time.john
Thanks john

 

Will do!

 

BTW, I checked for you. Yes the left and right bulbs share the power wire. Don't forget to disconnect all bulbs on one side b4 you check - they all share the same ground.

John

 

To clarify: You say left and right share the same power wire. Do you mean left and right taillights or left and right bulbs on the passenger circuit board?

 

Oh sorry, I mean that the hot wire to the tail light bulb on left also feeds the corresponding bulb on the right. I say this because there is no measurable resistance between them when: ignition off; bulbs removed from both tail light assenblies ; probe 1 on the left taillight socket, probe 2 on the right tail light socket = zero ohms.

Given this, the break in the power wire must come after the talilight power feed splits into 2 wires one for left, one for right.

 

Thank you. I will check the multi wire connector 1st for an open or bent pin.

 

It's fixed! This morning I rechecked the fuses 1st. According to the owners manual the fuse for the right taillight also powers the license plate lights in the trunk fuse box. Well, they weren't working as well. I replaced a 5 amp fuse and all's well! So.... I must have popped the fuse pulling off the the taillight board? Thanks for all the insight JohnKen!